It is highly desirable to be able to process waste or off-specification thin sheet material and to accomplish such at high rates of speed. A re-occurrent problem in attempting to accomplish the granulation of such materials, for example 1/2 mil polyethylene film, has been the tendency of this material to produce undesirable accordian-like folds or pleats when fed to the granulation chamber of a size reduction device type having a chamber and rotating rotor mounted therein in turn having knives fixed thereto for cooperating cutting relationship with stationary bed knives positioned at least on the downstroke side of the chamber. Various attempts to increase the granulation rate of such material such as the inclusion of further knife surfaces both of the rotating and fixed bed types, the increase in the rotor speed rates etc. have not met with the desired results inasmuch as the tendency of such material to accordian fold prevents sheet material from being consistently grasped by and fed into the rotor so as to enable such high throughput rates desired to be achieved. For instance, the material has been roped, that is, spirally wound prior to being fed to the chamber; but such has also not met with the desired results. It would accordingly be useful to provide a device which successfully enables the granulation of thin flexible film at high throughput rates while preventing such undesirable accordian fold tendencies.
Accordingly the principal object of the present invention is the provision of a granulator construction which will granulate thin flexible film material at high rates of speed and which is not limited by the inability of such device to receive sheet material to be processed.
A further object of the present invention is the provision of a graulator construction which enables the feeding of thin sheet material thereto in such a manner that undesirable accordian pleating is avoided.
A still further object of the invention is the provision of a manner of feeding such thin flexible sheet material to a granulator whereby such granulator is operated at least partially full of previously partially size reduced material and wherein the sheet material incoming to the chamber is positively driven in a generally radial direction towards the rotor on the downstroke side thereof while preventing the deflection of such sheet material away from said rotor by the rotational flow of the partially granulated material caused by the rotation of the rotor.
These and other objects of the invention are accomplished by the provision of a granulator having a closed chamber in which a rotor having a plurality of knives adapted for cooperative cutting relationship with a stationary knife or knives is mounted for rotation along a longitudinal axis thereof and wherein a pair of feed rolls are mounted directly above said chamber so as to enable feeding of sheet material directly towards said rotor in a generally radial direction thereto and wherein previously partially granulated material carried by the rotation of said rotor is deflected by a baffle downwardly projecting into the chamber towards said rotor but spaced therefrom.
Other objects and features of the invention will become more apparent with reference to the following drawings and the detailed description of the invention.